Immunotoxic effect of β-chlorolactic acid on murine splenocyte and peritoneal macrophage function in vitro

β-Chlorolactic acid is a major intermediate of 3-monochloro-1,2-propanediol (MCPD) in mammalian species, which a well-known by-product of acid-hydrolyzed soy sauce during its manufacturing process. β-Chlorolactic acid has not been studied on immunotoxicity. To evaluate the immunomodulatory effect of β-chlorolactic acid on murine splenocyte and macrophage in vitro, we investigated splenocyte blastogenesis by concanavalin A (Con A), anti-CD3 and lipopolysaccharide (LPS), the production of cytokines from splenocyte, and the activity of mouse peritoneal macrophages. β-Chlorolactic acid suppressed significantly splenic blastogenesis to Con A or anti-CD3 from 8.5 to 54.7% at doses comprised between 200 and 800 μM. β-Chlorolactic acid also suppressed significantly splenic blastogeneis to LPS from 8.5 to 71.5% at doses comprised between 200 and 800 μM. The production level of interferon (IFN)-g on splenocyte culture with Con A was significantly reduced from 21.5 to 51.4% at the higher concentration than 100 μM of β-chlorolactic acid. The levels of interleukin (IL)-2 and IL-4 were also decreased 22.6-58.4 and 10.2-36.6%, respectively, at high concentrations of β-chlorolactic acid. There was a significant decrease from 6.1 to 40.8% in the production of nitric oxide (NO) by peritoneal macrophages treated with 400-1000 μM β-chlorolactic acid. These results indicate that β-chlorolactic acid might be able to induce immunotoxic effect on immune response of lymphocytes and peritoneal macrophages in vitro.